Vehicular traffic congestion on roadways can be caused due to construction, stalled vehicles, accidents, events, or other causes. Gathering and distributing traffic data can be time-consuming and expensive. For example, some existing methods of gathering traffic data are based on helicopters, cameras, sensors, or drivers that communicate traffic conditions on particular roadways. As the number of roadways being monitored increase (e.g., in a large metropolitan area), the time and expense involved to gather and distribute traffic data also increase. Some existing methods to distribute traffic data are based on radio broadcasts or “mesh networks” (i.e., networks that distribute traffic data from one driver's mobile device to another using close-range wireless technology such as Bluetooth or “wifi”). At least one of the purposes of gathering and distributing traffic data is to enable drivers to avoid areas of traffic congestion. Improved methods of gathering and distributing traffic data are desirable.